Influence of dental materials on cells of the equine periodontium.

BACKGROUND: Therapy for equine periodontal disease can include filling of the periodontal pockets and widened interproximal spaces. Recommended dental materials are generally adopted from human dentistry. OBJECTIVES: To evaluate the biocompatibility of dental materials for equine periodontal fillings in vitro. STUDY DESIGN: In vitro experiments. METHODS: Four different dental materials (PeriCare® , Provicol® , Calxyl® and Honigum) were tested on equine periodontal fibroblasts. Possible cytotoxic effects were assessed microscopically and by MTT assay, and the expression of inflammatory marker genes was measured by qRT-PCR. RESULTS: PeriCare® and Provicol® had no effects on the cells, whereas Honigum and Calxyl® were associated with severe cytotoxic effects. MAIN LIMITATIONS: The results of this in vitro study need to be confirmed by clinical studies. CONCLUSIONS: Before adapting dental materials from human dentistry, it is crucial to initially test them in a specific equine model.

Infundibula of equine maxillary cheek teeth: Part 2: Morphological variations and pathological changes.

Incomplete cemental filling of the infundibula of equine maxillary cheek teeth (CT) is a common feature. Depending on the extent of the defect, three stages of infundibular decay have been suggested. However, histomorphological criteria to identify non-pathological abnormalities and destructive changes have not been defined. Six hundred and eighty eight CT with no evidence of dental diseases and 55 diseased permanent, fully erupted maxillary CT were evaluated on a macroscopic level by assessing the occlusal surface and horizontal sections, including porphyrin assays to detect residual blood within the infundibular cementum. Selected specimens were investigated on a microscopic level using routine and immunohistological staining methods to identify possible routes for the spread of infectious agents from the infundibulum into the endodontic system. Infundibular cemental hypoplasia was defined as a non-pathological developmental abnormality and was detected in >50% of CT with no evidence of dental diseases and in >70% of diseased CT. The first molar (Triadan 09) showed the highest prevalence (75%) of infundibular cemental hypoplasia. The mesial infundibulum was more often affected than the distal infundibulum. Infundibular erosion was considered as the most appropriate term to describe destructive infundibular changes. Infundibular erosion was present in <6% of CT with no evidence of dental diseases, but was detected in >27% of diseased teeth, always accompanied by endodontic disease. This suggests that teeth affected by infundibular cemental hypoplasia are prone to destructive erosion, which possibly leads to endodontic disease. Morphological factors that supplement this ethological hypothesis were described. In 74% of infundibula residual blood was identified, although no vital blood vessels were detected. It is assumed that this content of blood remained in the ample infundibular cemental blood system after tooth eruption and creates a favorable environment for microbial growth. The infundibular enamel was characterised by numerous infoldings to variable degrees and depths. In certain areas focal enamel aplasia was observed. These morphological features might contribute to microbiological settlement and spread of infectious agents through the infundibular wall into the endodontic system.

Infundibula of equine maxillary cheek teeth. Part 1: Development, blood supply and infundibular cementogenesis.

There is increasing interest in diseases of infundibula of equine maxillary cheek teeth. Imperfect infundibular cementogenesis has been recognized as an aetiopathological factor for the onset of infundibular necrosis. In this article, infundibular development was examined with particular attention to infundibular blood vessels and cementogenesis. Forty-one deciduous maxillary premolars prior to eruption were investigated using routine histological and immunohistological methods to visualize blood vessels and the enamel organ. Selected specimens were scanned by micro-computed tomography to analyze the three-dimensional configuration of the developing infundibulum. Before eruption, the infundibula are supplied by a central infundibular artery entering the infundibulum from an occlusal direction and by arteries entering the mesial infundibulum from the mesial aspect, and the distal infundibulum from the distal aspect. The central infundibular artery is destroyed shortly after tooth eruption but the lateral arteries remain vital for a time after eruption. As the arteries of the distal infundibulum are located in a more apical position, blood is received for a longer period compared with the mesial infundibulum. Cementogenesis starts first at distinct enamel in-foldings in the occlusal part of the infundibula, advancing in an apical direction. The results suggest a distinct asymmetry between the infundibula with the mesial infundibulum prone to incomplete cementogenesis due to early blood supply cessation.

Evaluation of mammographic and clinical follow-up after 755 stereotactic vacuum-assisted breast biopsies.

PURPOSE: Stereotactic vacuum-assisted breast biopsy (VB) is a new method that promises high accuracy and reliability. In order to avoid surgery in cases with benign histology the examination must be quality assured and the accuracy should be well established. We present follow-up data of 755 VBs with benign results. METHODS: In all, 984 of 1268 consecutive VBs proved histopathologically benign (lobular carcinoma in situ and atypical ductal hyperplasia not included). Follow-up data are available for 755 of 984 (77%) lesions and constitute the basis of this evaluation. Follow-up mammograms were performed of 728 lesions at 6 to 67 months (mean 24, median 17.8) after VB. RESULTS: Seven technically unsuccessful cases underwent immediate rebiopsy; 3 unsuccessful cases were diagnosed otherwise. No false negative occurred among the 752 followed-up, eventually successful VBs. On follow-up mammography 444 of 728 (61%) benign lesions proved radiologically completely removed, 284 (39%) partially. In 6 cases (0.8%) a surgical biopsy was performed again during the follow-up time confirming the benign result. No scar was seen in 96%, a slight scar in 3.8%, and a small stellate scar with possible diagnostic interference in 0.3%. CONCLUSIONS: A benign diagnosis of quality assured VB is very reliable and leads to no or minimal scarring.